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lu_siyah October 28, 2013 14:02

Extract Paraview data (vtkUnstructured Grid) using pvpython
I am working with large FE simulation data and I wish to extract information on only coordinates (at different timesteps, precisely a 3xN List of coordinates for every timestep considered or alternatively the displacements, which I know to be stored in a Point Array) and the basic connectivity of the grid into python arrays.
For now, I am working with Paraview in the pvpython-shell and vtk and struggling with finding and arranging the information. So far I used this code to get the coordinates in the beginning (data considered originates from LS-Dyna, hence 3dplot):

import numpy as np
from paraview import simple 
reader.PartArrays = ['Part1 (Matl2000001)']
# reader: <paraview.servermanager.LSDynaReader object at 0x376b5d0> 
data = simple.servermanager.Fetch(reader)
# data: (vtkMultiBlockDataSet)
grid = data.GetBlock(0)
# grid: (vtkUnstructuredGrid)
npoints = grid.GetNumberOfPoints()
coord = np.zeros((npoints,3))
for i in range(npoints):
  coord[i,:] = np.array(grid.GetPoint(i))

Any ideas on how to proceed from there? That is: Get a matrix of connectivities, and get acess to the data saved in the Point Arrays OR the coordinates at different time steps??
Any help will be appreciated as I am fairly new to this sort of programming.

wyldckat November 3, 2013 07:10

Greetings lu_siyah and welcome to the forum!

Sorry, I'm a bit confused with your description. Is what you're trying to do similar to what's described on this thread: :confused:

Because if I understand you correctly, you want to resample/probe the simulation volume you have from the FE simulation, with an array of point/probe locations.
The part that I don't understand is: why do you need a connectivity matrix?

Best regards,

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